The second auqastat was installed Monday afternoon, and the system has since been working great! As suspected, the first stat must have been defective. Thankfully the plumbing supply company exchanged it without cost. I have the high limit set at 180 and the low at 140. The timer clicks on the stoker for 2 min every 30 min. when the water temp is below 170 (180 minus the 10 degree differential)
It chomped down approx 100-150lbs of coal to get the floor up to temp but has been just "nibbling" away since. However, the outside temperature hasnt been too cold just yet, (low 40's for highs) but it dips into the 20's at night. According the the weather forecast, we'll give 'er a good workout this weekend.
Thanks for your help and input. Im sure I'll need some more to really get it dialed in.
PS... Still looking for a round door!